Which combination gives a wrestler the GREATEST stability? (a) Narrow base of support and a high centre of gravity (b) Wide base of support and a low centre of gravity (c) Wide base of support with the line of gravity at the very edge of the base (d) Narrow base of support and a low centre of gravity

Which combination gives a wrestler the GREATEST stability? (a) Narrow base of support and a high centre of gra

Concept understanding — Center of Mass Stability

Center of Mass Stability

Think about a toddler learning to walk. They stand with their feet wide apart, arms out, wobbling. They fall often. Now think of a sumo wrestler — low to the ground, legs spread, solid as a rock. What's the difference? It's not just practice. It's physics, and the key idea is center of mass stability.

The Intuition: The Balancing Point

Every object, including your own body, has a single point where its entire weight seems to be concentrated. That point is the center of mass. For a perfectly symmetrical object like a ball, it's right at the geometric center. For a human standing straight, it's roughly around your navel.

Now, stability is about whether that point stays inside your base of support — the area beneath you that is in contact with the ground. If your center of mass moves outside that base, you tip over. That's why a toddler falls: their center of mass is high (they're tall relative to their width) and their base is narrow (feet close together). A slight lean shifts the center of mass past their feet, and gravity does the rest.

Note

The base of support isn't just the area of your feet. If you use a walking stick, your base expands to include the area between your feet and the stick's contact point. That's why a stick helps you balance — it enlarges your stable zone.

What Makes Something Stable?

Three factors determine how stable an object is:

Height of the center of mass: Lower is more stable. A racing car is built low to the ground so it doesn't flip in a sharp turn. A tall lamp is easy to knock over because its center of mass is high.
Size of the base of support: Wider is more stable. A four-legged chair is harder to tip than a two-legged one. A person standing on one leg is less stable than on two.
Position of the center of mass relative to the base: The closer it is to the center of the base, the more stable. If you lean forward while standing, your center of mass moves toward the front of your feet. Lean too far, and you must step forward to catch yourself — you've moved your base under your shifting center of mass.

Important

Stability is not about being heavy. A heavy object with a high center of mass and a narrow base can be less stable than a light object that is low and wide. Think of a heavy vase on a thin pedestal versus a light, flat book on a table.

Why It Matters in Everyday Life …

Start your 14-day free trial to unlock the full solution →

A wrestler achieves the greatest stability by adopting a wide base of support and lowering their center of gravity, ensuring their line of gravity falls well within this base.

In wrestling, maintaining stability is crucial for resisting an opponent's force, executing moves, and preventing takedowns. Stability refers to the ability of a body to resist being moved from its position of equilibrium. It is primarily governed by two biomechanical principles: the base of support and the center of gravity.

The base of support (BOS) is the area enclosed by the points of contact that an object or person makes with the ground. For a wrestler, this includes the area between their feet, and potentially hands or other body parts if they are on the mat. A wider base of support provides a larger area over which the body's weight can be distributed, making it harder to be pushed or pulled off balance.

The center of gravity (COG), also known as the center of mass, is the imaginary point where the entire weight of an object appears to act. For a human body, this point shifts with changes in posture. A lower center of gravity increases stability because it means the body's weight is closer to the ground, requiring more force to tip it over. Think of a sumo wrestler's stance: wide and low.

The line of gravity (LOG) is an imaginary vertical line passing through the center of gravity. For maximum stability, the line of gravity must fall well within the base of support. If the line of gravity moves close to the edge of the base, or outside it, the body becomes unstable and will tend to fall.

Let's analyze the given options based on these principles:

(a) Narrow base of support and a high centre of gravity

A narrow base of support offers very little area for the line of gravity to shift without going outside the base, making the wrestler easily unbalanced. A high center of gravity further reduces stability because the body's weight is further from the ground, making it easier to tip over. This combination results in very low stability.
(b) Wide base of support and a low centre of gravity

A wide base of support provides a large area, allowing the line of gravity to shift considerably without exiting the base. A low center of gravity brings the body's weight closer to the ground, making it much harder to be tipped. This combination maximizes stability, which is highly desirable for a wrestler.
(c) Wide base of support with the line of gravity at the very edge of the base …

Start your 14-day free trial to unlock the full solution →

←Previous questionQ9 — What is friction? Explain its types with suitable examples.→Next questionQ10 — Explain the advantages and disadvantages of friction in sports. How ca…

Q.Which combination gives a wrestler the GREATEST stability?

🎓Unlock everything free for 14 days

Unlock everything free for 14 days